Fluid-operated clutch



May 20, 1969 w. H. CARSTENSEN ET AL 3,444,972

FLUID-OPERATED CLUTCH Filed April 28. 1967 INVENTOR WALTER H.CARSTENSENBY DONALD G. DAV v HA- 6M 1M. W

. ATTOKNEYS United States Patent US. Cl. 19285 8 Claims ABSTRACT OF THEDISCLOSURE A clutch mechanism for transmitting a high torque. A clutchshaft rotatable in either direction of which a portion can be extendedin an axial direction for engagement and disengagement with an apparatusthat is to be rotated.

The present invention relates to a clutch mechanism that is useful inthe manufacture of glass articles; more particularly, the presentinvention relates to a clutch that can be extended in an axial directionand at the same time can be engaged and disengaged while under theinfluence of a rotational force.

The invention as herein illustrated and described is specificallyadapted to the manufacture of hollow glass funnels or body members ofcathode ray picture tube envelopes for television reception andparticularly tube envelopes having a large overall configuration andmass. The present invention will be additionally appreciated becausethere has been an increase in the overall dimensions of viewing screensthrough the years thus necessitating more massive fabrication equipmentwhich inherently requires more power input. More recently, the so-calledwide-angle square-look tube envelopes have attained still furtherpopularity in providing both larger and more definitely rectangularcontoured viewing screens. The precisely formed rectangular tubes alsorequire a high power input if they are to be made to acceptabletolerances.

As presently manufactured, a cathode ray picture tube envelope or bulbis made by separately fabricating a hollow glass face plate whichprovides the viewing screen and a hollow glass funnel which constitutesthe tube portion. These parts are subsequently sealed together atcomplemental edges of similar contour as by thermal fusion or othersealing means.

More recently, the hollow funnel has been made by centrifugal moldingaction wherein a charge of molten glass is deposited in the apex area ofa hollow upwardlyfacing mold and the mold is immediately rotated aboutits vertical axis to form the hollow funnel. In order to rotate the moldand the glass charge during the spinning operation contained therein, asubstantial amount of torque is required. The accelerations achievedduring the initial spinning of a televsion funnel are of considerablemagnitude, hence the power input is necessarily quite large.

The instant invention now sets forth an improved clutch apparatus fordelivering the required power to a centrifugal cathode ray tube funnelspinning mold.

Briefly, the apparatus of the present invention includes a fixedexternally mountable clutch housing that contains in axial alignmenttherethrough a rotatable clutch shaft. The clutch shaft is supported bya combination of roller and sleeve bearings that are mounted within theclutch housing. In addition to its ability to rotate, part of thecentrally aligned clutch shaft can be extended and contracted in anaxial direction to engage and disengage the train of rotational powerfrom a power source to a power requiring apparatus such as a centrifugalspinning mold. The axial movement of the clutch shaft is achieved by theapplication of fluid pressure to one side or the other of a piston thatis attached to one end of the movable portion of the clutch shaft.

It is therefore an important object of the present invention to providean apparatus for the transfer of power from a power source to a moldthat is to be rotated under the influence of a substantial acceleration.

Another important object of this invention is to provide a powertransmitting clutch that can undergo controlled changes in axial lengthwhile rotating.

It is a further object of the instant invention to provide an apparatusfor delivering power to a centrifugal casting mold utilized in theformation of cathode ray tube funnels.

Yet another, and no less important, object of the present invention isto provide a clutch apparatus that can operate for sustained periods oftime and that also lends itself quite readily to maintenance and to thereplacement of parts.

Other objects of this invention will appear in the following descriptionand the appended claims wherein it will be apparent to those skilled inthe art that the following detailed description when taken inconjunction with the annexed drawing illustrates a preferred embodimentof the present invention.

On the accompanying drawing:

The single figure of the drawing shows a cross-sectioned elevationalview of the present apparatus.

Before explaining the present invention in detail, it is to beunderstood that this invention is not limited in its application in thefield of glass technology and that the details of construction and thearrangement of parts illustrated in the drawing are capable of otherembodiments and of being practiced and carried out in various ways notheretofore described. Also it is to be understood that the phraseologyor technology employed herein is for the purpose of description and notby Way of limitation.

Referring now to the drawing, an outer housing is represented by numeral10. The outer houSing is generally of an annular configuration with acentrally-located aperture that passes entirely through the outerhousing. The outer housing is normally cast to near final configurationand is made from a conventional material such as for example gray castiron. Positioned within outer housing 10 and in axial alignment with theaperture therethrough is a clutch body 11 that is capable of rotationand which is supported within the aperture that passes through outerhousing 10. In addition to its rotational capability, a portion ofclutch body 11 can be extended in an axial direction regardless ofwhether it is rotating or motionless. The engagement and disengagementcapability of the clutch mechanism is achieved by means of an extendibleclutch shaft 12 that is of smaller diameter than clutch body 11 and thatis almost entirely contained within clutch body 11. Thus it becomesapparent that when a rotational power source or input drive shaft suchas 13 is applied to one end of the clutch assembly, torque can betransmitted through the rotatable clutch body 11 and hence redeliveredat the other end in an engageable and disengageable fashion to anadjacent apparatus such as a centrifugal mold for the casting of glassarticles such as cathode ray tube funnels.

Referring to the drawing in more detail, it can be seen that clutch body11 is mounted for rotation within outer housing 10 by an upper bearing14 and a lower bearing 15. Bearings 14 and 15 are parallel to each otherand the planes of their races are normal to the longitudinal axis of theoverall clutch assembly. In addition to bearings 14 and 15, a sleevebearing 16 is aligned within outer housing and positioned between upperbearing 14 and lower bearing 15. A key 17 prevents rotation betweenbearing 16 and outer housing 10. The rotatable clutch body 11 is mountedfor rotation on bearings 14 and 15 and also sleeve bearing 16. In thismanner clutch body 11 can be maintained in precise alignment with aminimum amount of wear resulting, as will be commented upon infra. Therotatable clutch body 11 is held in axial alignment and positioned by abearing retainer nut that is aflixed to the lower threaded portion 21 ofclutch body 11. Bearing retainer nut 20 is held in locked engagementwith the threaded portion 21 of rotatable clutch body 11 by nutlock 24.The clutch body 11 is additionally held in position by a bearingretaining plate 22 which is aflixed by bolts 23 to the top portion ofthe outer housing 10. Thus it can be seen that the rotational clutchbody 11 is free to rotate while its axial movement is restricted bymeans of the bearing retainer nut 20 and bearing retaining plate 22.Bearings 14 and 15 are lubricated by conventional means not shownherein. Sleeve bearing 16 contains a film of oil on both its interiorand exterior surfaces. The actual mode of lubricating sleeve bearing 16will be pointed out hereinafter.

As previously mentioned, the present clutch assembly has the capabilityof undergoing an extension or contraction in an axial direction thuspermitting it to be engageable or disengageable with an adjacentapparatus. The extendible clutch shaft 12 is mounted within an axiallyaligned bore positioned within rotatable clutch body 11. Extendibleclutch shaft 12 is stabilized by a clutch shaft sleeve 27 which is, inturn, securely mounted withi the previously mentioned internal borelocated Within clutch body 11. The internal bore is represented bynumeral 25. The extendible clutch shaft sleeve 27 is also fixedly attached to the upper end of rotatable clutch body 11 by bolts 26. Theinternal bore 30 of extendible clutch shaft sleeve 27 contains a seriesof circumferentially-spaced axially aligned splines 31 which coact witha similar splined surface on the exterior of extendible clutch shaft 12.The mating between the splined surfaces of the extendible clutch shaft12 and the clutch shaft sleeve 27 permits axial movement and at the sametime restricts any circumferential movement between the two parts.

As can be seen in the drawing, extendible clutch shaft 12 is furtherstabilized by a mounting ring 32 which is positioned at the bottom endof clutch shaft sleeve 27. Mounting ring 32 is held in close fittingarrangement with a cylindrical portion 29 of extendible clutch shaft 12.In addition to providing a stabilizing influence, mounting ring 32 alsocontains an oil seal as depicted at 33. Located immediately below andadjacent to cylindrical portion 29 is still a smaller cylindricalsection 34. A piston plate 35 is attached to cylindrical section 34 bymeans of nut 36. Nut 36 is, of course, threaded to the lower termi nus40 of extendible clutch shaft 12. While piston plate 35 occupies aportion of internal bore which forms the internal surface of rotatableclutch body 11, it can be seen that there is a fluid receiving chamber41 positioned on the upper side of piston plate 35 and that there isalso a fluid receiving chamber 42 positioned on the lower side of pistonplate 35. Ingress and egress to chambers 41 and 42 are made by fluidinlets 43 and 44. Directing our attention to fluid inlet 43, a fluid canpass through outer housing 10 and to a circumferentially positionedgroove 45 on the interior of sleeve bearing 16. Inwardly directedpassages 46 carry the fluid into fluid receiving chamber 41. As thepressure builds up within fluid receiving chamber 41, it acts upon thetop surface of piston plate 35 thus urging it in a downward direction.This, of course, will cause extendible clutch shaft 12 to be drawnwithin the overall clutch assembly. In a similar fashion a fluid can beintroduced through fluid inlet 44 and communicated to fluid receivingchamber 42 by way of groove 47 and passage 48. The force of the fluid inthe fluid receiving chamber 42 will act upon the lower surface of pistonplate 35 thus forcing extendible clutch shaft 12 in an outward orextendible position so that it may engage an object that is to berotated.

The proper valving associated with the ingress and egress of the fluidsto and from fluid chambers 41 and 42 is of conventional means and neednot be described herein.

It can also be ascertained that a constant pressure can be maintainedwithin fluid receiving chamber 41 or 42 while the rotatable clutch body11 is moving in a rotational manner. This is, of course, achieved by thefact that grooves 45 and 47 extend the entire way around the internalsurface of stationary clutch sleeve 16.

The fluid that passes through passage 46 can also travel to a limitedextent along both sides of sleeve 16 thus keeping sleeve 16 suspended inan oil cushion. O-rings such as 18 are positioned in grooves in theoutside surface of sleeve 16 thus providing a resilient seal in bothsides of grooves 45 and 47. In addition to sealing, O-rings 18 help inmaintaining the floating action of sleeve 16. The lubricant that passesbeyond the ends of sleeve 16 is conveyed into the oil housing chambersassociated with bear lugs 14 and.15. By having sleeve 16 suspended in anoil bath, wear on both the sleeve 16 and rotatable clutch body 11 arekept at a minimum.

While certain representative embodiments and details have been shown forthe purpose of illustrating the invention, it will be apparent to thoseskilled in this art that various changes and modifications may be madetherein without departing from the spirit or scope of the invention.

What is claimed is:

1. A clutch apparatus for transmitting a rotational movement from oneapparatus to another comprising:

external frame means having a longitudinal axis therethrough;

an annular aperture coincident with said axis that extends through saidframe means;

a clutch body positioned within said aperture and adapted for rotation;

means associated with one end of said clutch body for receiving arotational force;

fixed bearing means interdisposed between said frame means and saidclutch body, said fixed bearing means being positioned toward theextremities of said clutch body and a floating sleeve bearing positionedaxially bet-ween said fixed bearing means;

an axially extendible and contractible clutch shaft mounted within saidclutch body and including an end portion projecting axially therefrom;

means to prevent relative rotation between said clutch body and saidclutch shaft; means connected to said clutch shaft end portion for thedelivery of a torque to an adjacent torque receiving apparatus; and

fluid means coupled at one end of said clutch shaft for movement thereofin an axial direction with respect to said clutch body.

2. A clutch apparatus for transmitting a rotational force from oneapparatus to another comprising:

external frame means having a longitudinal axis therethrough;

an annular aperture coincident with said axis that extends through saidframe means;

a clutch body positioned within said aperture and adapted for rotation;

means associated with one end of said clutch body for receiving arotational force;

fixed bearing means interdisposed between said frame means and saidclutch body, said fixed bearing means being positioned toward theextremities of said clutch body and an annular floating sleeve bearingpositioned axially bet-ween said fixed bearing means;

an axially extendible and contractible clutch shaft having an externalend and an internal end mounted withing said clutch body;

means to prevent relative rotation between said clutch body and saidclutch shaft;

a plurality of circumferentially spaced longitudinally extending teethpositioned on the external end of said clutch shaft; and

a piston affixed at the internal end of said clutch shaft for elfectingmovement of said clutch shaft in an axial direction with respect to saidclutch body.

3. A clutch apparatus for transmitting a rotational force from oneapparatus to another comprising:

external frame means having a longitudinal axis therethrough;

an aperture coincident with said axis that extends through said framemeans and which is comprised of a plurality of circular surfaces;

a clutch body positioned within said aperture and adapted for rotation;

means associated with one end of said clutch body for receiving arotational force;

fixed bearing means interdisposed between said frame means and saidclutch body, said fixed bearing means being positioned toward theextremities of said clutch body and an annular floating sleeve bearingpositioned axially between said fixed bearing means;

an axially extendible and contractible clutch shaft having an externalend and an internal end mounted within said clutch body;

a plurality of circumferentially spaced longitudinally extending teethpositioned on the external end of said clutch shaft;

a piston affixed at the internal end of said clutch shaft for effectingmovement of said clutch shaft in an axial direction with respect to saidclutch body; and

fluid chamber means positioned within said clutch body and on eitherside of said piston, said fluid chamber means communicating :withexternal fluid inlets positioned in said external frame means.

4. An apparatus as set forth in claim 3 wherein said clutch shaft isheld against rotation with respect to said clutch body by a plurality ofaxially aligned circumferentially spaced splines located on the externalsurface of said clutch shaft and on the interior of said clutch body.

5. An apparatus as claimed in claim 4 wherein said sleeve bearing isheld against rotation by key means fixed with respect to said framemeans.

6. An apparatus as claimed in claim 4 wherein said sleeve bearing floatswith respect to said frame means and said clutch body.

7. An apparatus as claimed in claim 4 wherein the input torque to saidclutch body is received by an internally splined annular orifice in saidclutch body at the end thereof remote from said clutch shaft.

8. An apparatus as claimed in claim 7 wherein a plural ity of O-ringsare positioned in grooves around the external surface of said sleevebearing to facilitate the sealing and floating action thereof.

References Cited UNITED STATES PATENTS 2,578,094 12/1951 Sears.

2,753,729 7/1956 Main 19286 X 3,106,343 10/ 196-3 Holland 19296 XFOREIGN PATENTS 1,191,221 10/1959 France.

BENJAMIN W. WYCHE III, Primary Examiner.

U.S. Cl. X.R.

